Generally, a scroll compressor is widely applied to an air conditioning system with a high efficiency and low noise. In the scroll compressor, two scrolls perform a relative orbiting motion, and a pair of compression chambers are formed between the two scrolls. While consecutively moving towards the centers of the scrolls, the compression chambers have a decreased volume thereby to suck, compress and discharge a refrigerant.
The scroll compressor may be divided into a low pressure type scroll compressor and a high pressure type scroll compressor according to whether suction gas is filled in a casing.
As shown in FIG. 1, the high pressure type scroll compressor comprises: a casing 1 maintaining a high pressure state, and having a gas discharge pipe DP; a main frame 2 and a sub frame 3 fixed to upper and lower sides inside the casing 1, respectively; a driving motor 4 disposed between the main frame 2 and the sub frame 3, for generating a rotation force; a fixed scroll 5 fixed to an upper surface of the main frame 2, and to which a gas suction pipe SP is directly coupled; an orbiting scroll 6 orbitably disposed on an upper surface of the main frame 2 so that a plurality of compression chambers P can be formed by being engaged with the fixed scroll 5; and an Oldham ring 7 disposed between the orbiting scroll 6 and the main frame 2, for orbiting the orbiting scroll 6 with preventing a rotation of the orbiting scroll 6.
At an upper space S1 of the casing 1 based on the main frame 2, the gas suction pipe SP is installed to be directly communicated with an inlet 5b of the fixed scroll 5. On the contrary, at a lower space S2 of the casing based on the main frame 2, the gas discharge pipe DP is installed.
An outer circumferential surface of the main frame 2 is adhered to an inner circumferential surface of the casing 1, and is fixed thereto by a welding. The gas discharge pipe DP is disposed on the outer circumferential surface of the main frame 2. A plurality of gas communication recesses 2a are formed so that gas discharged through the fixed scroll 5 can be introduced into the gas discharge pipe DP.
An unexplained reference numeral 4A denotes a stator, 4B denotes a rotor, 4C denotes a driving shaft, 5a denotes a fixed wrap, 5C denotes an outlet, 6a denotes an orbiting wrap, C1 denotes an upper winding coil, and C2 denotes a lower winding coil.
An operation of the conventional high pressure type scroll will be explained.
When power is supplied to the driving motor 4, the driving shaft 4C is rotated together with the rotor 4B, and the orbiting scroll 6 is orbited on an upper surface of the main frame 2 by the Oldham ring as much as an eccentric distance. A plurality of paired compression chambers P moving towards the center of the scroll compressor are consecutively formed between the fixed wrap 5a of the fixed scroll 5 and the orbiting wrap 6a of the orbiting scroll 6. While the orbiting scroll 6 continues to perform an orbiting motion, the plurality of paired compression chambers P have decreased volumes towards the center of the scroll. Accordingly, a refrigerant is sucked, compressed, and discharged.
A refrigerant is sucked into the inlet 5b of the fixed scroll 5 through the gas suction pipe SP, is compressed at a compression chamber P, and then is discharged to the upper space of the casing 1 through the outlet 5c of the fixed scroll 5. A refrigerant discharged to the upper space S1 of the casing 1 is moved to the lower space S2 of the casing 1 via the gas communication recess 2a of the main frame 2, and then is discharged to a refrigerating cycle system through the gas discharge pipe DP.
On the contrary, oil is sucked through an oil flow path of the driving shaft 5 by a centrifugal force when the driving shaft 5 is fast rotated, thereby being supplied to each surface to be lubricated. Then, the oil having performed a lubricating operation is recollected to a bottom of the casing 1 together with oil separated from a refrigerant discharged from the compression chamber P.